2026/01/11 DPA: "By Hook Or By Qrook"

White to move:

.

Black's King is stuck on the edge with no escape squares.

Black threatens -M1 [1. ... Rg1#] so White must act expeditiously.

1. Nc6+ would be checkmate but both the Knight and LSB are guarding c6.

1. Ra8+ Bxa8. 2. Qc7+ Bb7. 3. Nc6+ Nxc6  4. Qxb7#.

Oh, wait:  4. Qxb7+ is not checkmate because the Knight is blocking White's Bishop from attacking b7.

But this feels like the right track.

We also have to consider the possibility that this is a material gain puzzle with 1. Qxd1.  Then again, 1. ... Bxe4 looks very unpleasant.

If there was a way to protect b8 [ie if White had a Bishop on f4], then 1. Ra8+ Kxa8. 2. Qc8+ Ka7. 3. Qb8#.

But there is no DSB and I don't see a way of getting a Knight to, say d7, without losing tempo and allowing ... Rg1#.

There are only 2 checks:  1. Nc6+, which just loses the Knight, and 1. Ra8+.

The only alternative to not checking is 1. Bxf3, which allows 1. ... Bxf3+. 2. Kh2 Rh1#.

So it must start with a check [assuming we can rule out 1. Qxd1] and 1. Ra8+ is the only one that makes sense.

1. Ra8+ Bxa8 [we'll look at 1. ... Kxa8 later].

What other check exists besides 2. Qc7+?  Only 2. Nc6 but again, doesn't that just lose the Knight?

Does 1. Nc6+ offer any hope?  1. ... Nxc6. 2. Ra8+ Kxa8 and now White doesn't even have 3. Qc8+ due to the Black Knight now blocking the c file.

1. Ra8+ Bxa8. 2. Qc7+ Bb7. 3. Qxb7+ Nxb7. 4. Nc6+ Ka8. 5. Nc7#.

And if 1. ... Kxa8. 2. Qc8+ [exploiting the pin] Ka7 and White uses the same moves as above.

This 2nd line will probably be chosen due to the pin.

I was right.

.

The keys were recognizing:

• that a check was the only way to start the solution
  • any other move led to 1. ... Rg1# except 1. Bxf3, which led to 1. ... Bxf3+. 2. Kh2 Rh1#
• that the Rook sac was the only reasonable check
• that the King would likely capture but that 2. Qc8 could exploit the pin on the Bishop so it could not capture
• that the Queen sac removed both defenders of c6 in one move:  by capturing the Bishop and forcing the Knight to recapture
• that the King only had 2 escape squares and the Knights could combine for the checkmate

1. Ra8+ allows the Queen to move with check

2. Qc8+ relies on the fact that the Black Bishop is pinned and thus cannot capture the Queen

3. Qxb7+ removes one defender of c6 and forces the Knight to recapture, which removes the other defender of c6; very slick!

4. Nc6+:  at last, the Knight swoops in.  This also removes b8 as an escape.

5. Nc7#:  the second steed finishes the deed.

I got stuck for a while because I didn't give enough thought to saccing the Queen.